Apparatus for the electrolytic treatment of metallic pieces

ABSTRACT

The apparatus comprises a movable electrode disposed near to the work piece to be treated, a current generator whose two terminals are respectively connected to the electrode and to the work piece, and supply means for depositing an electrolyte between the workpiece and the electrode. Deflection means are provided for giving the layer of electrolyte the character of a thin film. These deflection means can be in the form of a blade, flexible or rigid, urged elastically against the electrode, or in the form of a gaseous jet tangent to or striking the electrode at a point between the supply means and the workpiece.

United States Patent APPARATUS FOR THE ELECTROLYTIC TREATMENT OF METALLIC PIECES 6 Claims, 5 Drawing Figs.

US. Cl 204/212, 204/143, 204/224 Int. CL C231: 5/68, 823p 1/00, 823p 1/02 Field of Search 204/212,

Primary Examiner-John l-l. Mack Assistant ExaminerT. Tufariello Att0rneyLarson, Taylor & Hinds ABSTRACT: The apparatus comprises a movable electrode disposed near to the work piece to be treated, a current generator whose two terminals are respectively connected to the electrode and to the work piece, and supply means for depositing an electrolyte between the workpiece and the electrode. Deflection means are provided for giving the layer of electrolyte the character of a thin film. These deflection means can be in the form of a blade, flexible or rigid, urged elastically against the electrode, or in the form of a gaseous jet tangent to or striking the electrode at a point between the supply means and the workpiece.

APPARATUS FOR THE ELECTROLYTIC TREATMENT OF METALLIC PIECES This invention relates to apparatus for the electrolytic treatment of metallic pieces, that is to say for removing a certain quantity of the metal constituting the piece subjected to the treatment or for depositing on that piece a certain quantity of a partly metallic material. The apparatus to which the present invention is directed comprises at least one electrode movable with respect to the piece to be treated and disposed near to this piece, a current generator whose two terminals are respectively connected to the movable electrode and to the piece to be treated, and supply means arranged so as to bring an electrolyte of composition appropriate for the treatment envisaged to occupy the space comprised between the piece to be treated and the movable electrode. The invention is more particularly, but not exclusively, concerned with apparatus of this type intended for the electrolytic treatment consisting of removing a certain quantity of the metal constituting the piece to be treated.

In apparatus of the type mentioned above, the electrolytic treatment takes place in the regions where an intimate connection between the piece to be treated and the movable electrode is ensured by the electrolyte.

Now, in such apparatus known hitherto, the supply means deposited the electrolyte on the movable electrode in the form of a relatively thick layer.

This relative thickness of the layer and the small value that it is appropriate to give to the distance between the movable electrode and the piece to be treated in order that the treatment envisaged can be effected in favorable conditions (minimum duration of the treatment and minimum consumption of energy) were then the cause of an accumulation of electrolyte outside of the space separating the movable electrode from the piece to be treated, which accumulation did not permit the localization of the treatment in a precise manner, that is to say to only the part of the piece to be treated facing the movable electrode.

The chief object of this invention is to provide apparatus of the type in question which fulfills, the various requirements of practice, and in particular, which permits the localization of the treatment in a precise manner while avoiding the accumulation of electrolyte outside of the space separating the movable electrode from the piece to be treated.

Apparatus of the type in question comprises deflection means acting on the flow of electrolyte between the supply means and the space comprised between the piece to be treated and the movable electrode, these deflection means being arranged so as to cause a decrease of the thickness of the layer of electrolyte deposited on the movable electrode by said supply means, so that this layer of electrolyte has the character of a thin film and preserves this thin film character at least as far as the space comprised between the piece to be treated and the movable electrode.

In one class of embodiment, the invention is characterized by the fact that these deflection means comprise essentially, on the one hand, a pressure element constituted by a flexible blade or by a rigid blade, and on the other hand, elastic return means arranged so as to bear this pressure element against the movable electrode.

In another class of embodiment, the invention is characterized by the fact that the deflection means are of thegaseous jet" type and comprise essentially at least one nozzle delivering a gaseous jet at high speed, this nozzle being oriented so that the gaseous jet is tangent to or strikes the movable electrode, the point of tangency or the point of impact of the gaseous jet on the movable electrode being situated between the supply means and the piece to be treated.

Various other features and characteristics of the invention will become apparent from the following specific description, given merely by way of example, with reference to the accompanying drawings, in which:

FIG. I shows a schematic view of an apparatus according to a first embodiment of the invention;

FIG. 2 is an enlarged view explaining the operations of the apparatus shown in FIG. I;

FIGS. 3 to 5 illustrate respectively, by partial schematic views, other embodiments of the invention.

The embodiments shown in the drawings relate to apparatus for the electrolytic treatment of metallic pieces consisting of removing a certain quantity of the metal constituting the piece to be treated. Such apparatus comprises, as shown in FIGS. 1 to 5,

and electrode 1 movable with respect to the piece to be treated 2 and disposed near to this piece, this movable electrode 1 being advantageously constituted by a disc rotating about its axis and carried by a mechanism 3 arranged in a manner to communicate to the movable electrode l a movement tending to move this electrode towards the piece to be treated 2.

a current generator 4, preferably a continuous current generator, whose negative terminal is connected to the movable electrode 1 and whose positive terminal is connected to the piece to be treated 2, 1

and supply means 5 arranged so as to bring an electrolyte 6 of composition appropriate for the treatment envisaged to occupy the space 7 comprised between the piece to be treated 2 and the movable electrode 1.

It is appropriate to point out that the disc constituting the movable electrode 1 can be entirely or partially metallic and that it can be or not charged with an abrasive.

In addition, this apparatus comprises deflection means 8 acting on the flow of electrolyte 6 between the supply means 5 and the space 7 comprised between the piece to be treated 2 and the movable electrode 1, these deflection means 8 being arranged so as to cause a decrease of the thickness of the layer of electrolyte 6 deposited on the movable electrode 1 by these supply means 5, so that this layer of electrolyte 6 has the character of a thin film 9 and preserves this thin film character at least as far as the space 7 comprised between the piece to be treated 2 and the movable electrode 1.

It will then be appreciated that when the thin film 9 caused by the deflection means 8 engages in the space 7 comprised between the piece to be treated 2 and the movable electrode 1, practically the entire film of electrolyte can engage in this space 7 without causing the accumulation of electrolyte of which the undesirable effects have been evoked above. At the most, as shown in FIG. 2, there can be produced an effect of scraping of the thin film 9 by the end of the piece to be treated which is touched the first by this thin film. This scraping effect causes a clean and sudden break of the peripheral part of the thin film 9, which peripheral part is then evacuated superficially over the surface of the piece to be treated in the form of a pellicle which runs along this surface. This pellicle is generally transformed, under the effect of capillary forces, into drops of electrolyte whose evacuation can easily be effected by blowing or aspiration.

Furthermore, it is appropriate to mention that the clean break of the peripheral part of the thin film 9 is favored by the fact that this thin film 9 is driven with a speed at least equal to the tangential speed of the movable electrode 1 at the level of its greatest radius.

In the embodiments illustrated in FIGS. 1 and 3, the deflection means 8 are of the mechanical type and comprise essentially,

a pressure element 10 constituted by a flexible blade (FIG.

1) or by a rigid blade (FIG. 3),

return means ll arranged so as to bear this pressure element [0 against the movable electrode 1, these return means 11 being constituted by an elastic blade (FIG. I) or by a helical spring (FIG. 3).

In the embodiments illustrated in FIGS. 4 and 5, the deflection means 8 are of the gaseous jet" type, and comprise essentially at least one nozzle 12 delivering a gaseous jet 13 at high speed, this nozzle 12 being oriented so that the gaseous jet 13 is tangent to the movable electrode 1 (FIG 4) or strikes the movable electrode 1 (FIG 5), the point of tangency or the point of impact of this gaseous jet 13 on the movable electrode 1 being situated between the supply means 5 and the piece to be treated 2.

It can be seen from the foregoing that the present invention provides apparatus for the electrolytic treatment of metallic pieces for removing a certain quantity of the metal constituting the piece to be treated which permits the localization of the treatment in an extremely precise manner, and, accordingly, permits the realization of very tine machining.

Although this invention has been described with specific reference to apparatus for removing metal from the piece to be treated, the invention can equally well be applied to apparatus for depositing on a piece to be treated a certain quantity of a partly metallic material.

in addition, many other variations and modifications are possible without departing from the spirit or the scope of this invention, so that the invention should not be limited to the particular embodiments described by way of example.

What I claim is:

1. Apparatus for the electrolytic treatment of metallic elements comprising, at least one electrode movable with respect to the element to be treated and disposed adjacent the ele' ment to be treated, a current generator having first and second terminals respectively connected to the movable electrode and to the element to be treated, supply means for supplying an electrolyte of a composition appropriate for the treatment envisaged to the space located between the element to be treated and the movable electrode, and deflection means for acting on the flow of electrolyte between the supply means and'the space located between the element to be treated and the movable electrode so as to cause a decrease in the thickness of the layer of electrolyte deposited on the movable electrode by the supply means such that the layer of electrolyte has the character of a thin film and preserves this thin film character as far as the space located between the piece to be treated and the movable electrode, said deflection means comprising a pressure member comprising a blade, and resilient means for urging said pressure member towards said movable electrode, the angle between the pressure element and an extension of the vector representing the tangential velocity of the movable electrode in the area of said pressure member being less than 90 so that a wedge of electrolyte is formed between the pressure member and the movable electrode.

2. Apparatus according to claim 1 wherein said pressure member comprises a flexible blade and said resilient means comprises a resilient blade.

an electrolyte of a composition appropriate for the treatment,

envisaged to the space located between the element to be treated and the movable electrode, and deflection means for acting on the flow of electrolyte between the supply means and the space said at between the element to be treated and the movable electrode so as to cause a decrease in the thickness of the layer of electrolyte deposited on the movable electrode by said supply means such that the layer of electrolyte has the character of a thin film and preserves this thin film character so far as the space located between the piece to be treated and the movable electrode, said deflection means comprising at least one nozzle for delivering a gaseous jet at high speed, said at least one nozzle being oriented such that the gaseous jet makes contact with the movable electrode, the point of contact between the gaseous jet and the movable electrode being located between the supply means and the element to be treated and the angle between the gaseous jet and an extension of the vector representing the tangential velocity of the movable electrode in the area of said pressure element being less that so that a wedge of electrolyte is formed between the gaseous yet and the movable electrode.

5. Apparatus according to claim 4, wherein said at least one nozzle is oriented so that said gaseous jet is tangent to the movable electrode, the point of tangency then being said point of contact.

6. Apparatus according to claim 4, wherein said at least one nozzle is oriented so that said gaseous jet strikes the movable electrode, the point of striking then being said point of contact.

* II t O 

2. Apparatus according to claim 1 wherein said presSure member comprises a flexible blade and said resilient means comprises a resilient blade.
 3. Apparatus according to claim 1 wherein said pressure member comprises a rigid blade and said resilient means comprises a helical spring.
 4. Apparatus for the electrolytic treatment of metallic elements comprising at least one electrode movable with respect to the element to be treated and disposed adjacent to the element to be treated, a current generator having first and second terminals respectively connected to the movable electrode and to the element to be treated, supply means for supplying an electrolyte of a composition appropriate for the treatment envisaged to the space located between the element to be treated and the movable electrode, and deflection means for acting on the flow of electrolyte between the supply means and the space said at between the element to be treated and the movable electrode so as to cause a decrease in the thickness of the layer of electrolyte deposited on the movable electrode by said supply means such that the layer of electrolyte has the character of a thin film and preserves this thin film character so far as the space located between the piece to be treated and the movable electrode, said deflection means comprising at least one nozzle for delivering a gaseous jet at high speed, said at least one nozzle being oriented such that the gaseous jet makes contact with the movable electrode, the point of contact between the gaseous jet and the movable electrode being located between the supply means and the element to be treated and the angle between the gaseous jet and an extension of the vector representing the tangential velocity of the movable electrode in the area of said pressure element being less that 90* so that a wedge of electrolyte is formed between the gaseous jet and the movable electrode.
 5. Apparatus according to claim 4, wherein said at least one nozzle is oriented so that said gaseous jet is tangent to the movable electrode, the point of tangency then being said point of contact.
 6. Apparatus according to claim 4, wherein said at least one nozzle is oriented so that said gaseous jet strikes the movable electrode, the point of striking then being said point of contact. 